And why wasn't he nearly as popular as guys like Tyson even though he had tons of knockouts and a style that is nice to watch
I have no idea what he did with his money, but I do know why he wasn't as popular as Tyson was. He defended his belt against an clearly over the hill Dokes, while he ducked #1 contender Lewis in the most clear way possible. And defended next against Jesse "Journeyman" Ferguson (who was beaten by Dokes a year before)... Then he had his first real defence against Holyfield and lost his belts again. Tyson on the other hand fought all comers and dismissed them in brutal fashion.
If I remember right Bowe was always up to his neck in legal disputes of one form or another. I'm sure this was a factor in his money problems.
Good question. I read that Newman made him a fortune as he managed and his brother often acted as promoter enabling them in keeping the "lion's share" of everything like in the Ferguson fight.